U.S. patent number RE40,610 [Application Number 10/815,194] was granted by the patent office on 2008-12-23 for digital camera with moveable image pickup device.
This patent grant is currently assigned to Hoya Corporation. Invention is credited to Tetsuji Shono.
United States Patent |
RE40,610 |
Shono |
December 23, 2008 |
Digital camera with moveable image pickup device
Abstract
A digital camera which includes: a photographic lens movable
along an optical axis thereof between a retracted position and a
photographing position in front of the retracted position; an image
pick-up device on which an object image is formed through the
photographic lens, the image pick-up device being guided to be
movable between a first position where the image pick-up device is
positioned in a photographic optical path of the photographic lens
behind the photographic lens and a second position where the image
pick-up device is positioned out of the photographic optical path;
and a mechanism for moving the image pick-up device between the
first position and the second position, wherein the moving
mechanism moves the image pick-up device to the first position when
the photographic lens is moved from the retracted position to the
photographing position, and wherein the moving mechanism moves the
image pick-up device to the second position when the photographic
lens is moved from the photographing position to the retracted
position.
Inventors: |
Shono; Tetsuji (Saitama,
JP) |
Assignee: |
Hoya Corporation (Tokyo,
JP)
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Family
ID: |
15599511 |
Appl.
No.: |
10/815,194 |
Filed: |
April 1, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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Reissue of: |
09089404 |
Jun 3, 1998 |
06366323 |
Apr 2, 2002 |
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Foreign Application Priority Data
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Jun 12, 1997 [JP] |
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9-155144 |
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Current U.S.
Class: |
348/360; 348/374;
348/E5.027; 396/270; 396/349; 396/75; 348/E5.025; 348/373; 348/357;
348/340; 348/335 |
Current CPC
Class: |
H04N
5/2253 (20130101); H04N 5/2254 (20130101); G02B
7/102 (20130101) |
Current International
Class: |
H04N
5/225 (20060101); G02B 13/16 (20060101); G02B
7/10 (20060101); G03B 17/04 (20060101); G03B
5/02 (20060101); H04N 5/232 (20060101) |
Field of
Search: |
;348/208.1,344,208.99,219.1,240.99,240.3,262,335,340,357,360,361,369,374
;396/75,349,350,270,361 ;250/208.1 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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3317999 |
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Nov 1983 |
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DE |
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1 9623066 |
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Dec 1997 |
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DE |
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000549300 |
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Jun 1993 |
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EP |
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0598703 |
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May 1994 |
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EP |
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0634680 |
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EP |
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0810466 |
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EP |
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2261298 |
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May 1993 |
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GB |
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2262356 |
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2394787 |
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2309551 |
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2344661 |
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2344662 |
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58-10708 |
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58-145930 |
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58-162914 |
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61-69002 |
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61-133933 |
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61-270737 |
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63-149629 |
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64-34623 |
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Mar 1989 |
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5-313226 |
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Nov 1993 |
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JP |
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6-18777 |
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Jan 1994 |
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JP |
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06230263 |
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Aug 1994 |
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JP |
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406230263 |
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Aug 1994 |
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JP |
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06303497 |
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Oct 1994 |
|
JP |
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406303497 |
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Oct 1994 |
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JP |
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6-308592 |
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Nov 1994 |
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JP |
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7-191249 |
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Jul 1995 |
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JP |
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7-199019 |
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Aug 1995 |
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JP |
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7-288724 |
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Oct 1995 |
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JP |
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7-295050 |
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Nov 1995 |
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JP |
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08009230 |
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Jan 1996 |
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JP |
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0816759 |
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Jul 1996 |
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JP |
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008126759 |
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Jul 1996 |
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JP |
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008237529 |
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Sep 1996 |
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JP |
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08237529 |
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Sep 1996 |
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JP |
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08313790 |
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Nov 1996 |
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JP |
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09-5849 |
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Jan 1997 |
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JP |
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9-15682 |
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Jan 1997 |
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JP |
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10-32740 |
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Feb 1998 |
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JP |
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10254054 |
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Sep 1998 |
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JP |
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10-282394 |
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Oct 1998 |
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JP |
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11-109203 |
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Apr 1999 |
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JP |
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2002-023002 |
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Jan 2000 |
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JP |
|
2002-277719 |
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Sep 2002 |
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JP |
|
2003-114473 |
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Apr 2003 |
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JP |
|
2003149723 |
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May 2003 |
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JP |
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2003-207709 |
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Jul 2003 |
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JP |
|
2004-257555 |
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Sep 2004 |
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JP |
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Other References
English language Abstract of JP 9-15682. cited by other .
English language Abstract of JP6-308592. cited by other .
English Language Abstract of JP 61-133933. cited by other .
English Language Abstract JP 58-10708. cited by other .
English Language Abstract of JP 2003-207709. cited by other .
English Language Abstract of JP 2002-277719. cited by other .
English Language Abstract of JP 10-282394. cited by other .
Engliish Language Abstract of JP 58-162914. cited by other.
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Primary Examiner: Villecco; John M
Attorney, Agent or Firm: Greenblum & Bernstein,
P.L.C.
Claims
What is claimed is:
1. A digital camera comprising: a photographic lens movable along
an optical axis thereof between a retracted position and a
photographing position in front of said retracted position; image
pick-up device on which an object image is formed through said
photographic lens, said image pick-up device being guided to be
movable between a first position where said image pick-up device is
positioned in a photographic optical path of said photographic lens
behind said photographic lens and a second position where said
image pick-up device is positioned out of said photographic optical
path; and a mechanism for moving said image pick-up device between
said first position and said second position, wherein said moving
mechanism moves said image pick-up device to said first position
when said photographic lens is moved from said retracted position
to said photographing position, and wherein said moving mechanism
moves said image pick-up device to said second position when said
photographic lens is moved from said photographing position to said
retracted position.
2. The digital camera according to claim 1, wherein said image
pick-up device is guided in a direction perpendicular to said
optical axis.
3. The digital camera according to claim 1, wherein said moving
mechanism moves said image pick-up device from said first position
to said second position before said photographic lens reaches said
retracted position.
4. The digital camera according to claim 3, wherein a rear end of
said photographic lens moves into a space previously occupied by
said image pick-up device when said photographic lens moves from
said photographing position to L1 said retracted position.
5. The digital camera according to claim 1, wherein said moving
mechanism comprises a support plate to which the image pick-up
device is secured, said support plate being pivoted about a shaft
secured to a body of said digital camera so that said image pick-up
device is movable between said first position and said second
position.
6. The digital camera according to claim 5, wherein said shaft
extends parallel to said optical axis.
7. The digital camera according to claim 1, wherein said
photographic lens comprises: a lens barrel movable along said
optical axis between said retracted position and said photographing
position; and a photographic optical system comprising a front lens
group and a rear lens group, at least said rear lens group being
supported by said movable lens barrel; wherein said moving
mechanism further comprises an interlocking mechanism, provided
between said image pick-up device and said movable lens barrel, for
moving said image pick-up device between said first position and
said second position in association with the movement of said
movable lens barrel between said photographing position and said
retracted position.
8. The digital camera according to claim 5, wherein said moving
mechanism further comprises a spring for continuously urging said
support plate in a direction to move said image pick-up device to
said first position.
9. The digital camera according to claim 5, wherein said
photographic lens is a motor-driven zoom lens, said moving
mechanism further comprises: a cam plate guided in a direction
perpendicular to the optical axis, said cam plate being moved in
association with the movement of said photographic lens; and an
interlocking mechanism, provided between said image pick-up device
and said cam plate, for moving said image pick-up device between
said first position and said second position in association with
the movement of said cam plate.
10. The digital camera according to claim 9, further comprising: a
zoom finder which varies a magnification thereof in association of
the variation of a focal length of said photographic lens, said
zoom finder comprising at least one movable lens group having a
follower, wherein said cam plate comprises a cam slot in which said
follower is fitted.
11. The digital camera according to claim 10, further comprising: a
strobe which varies an angle of illumination thereof in association
of said variation of said focal length of said photographic lens,
said strobe comprising a movable light emitting unit having a
second follower, wherein said cam plate comprises a second cam slot
in which said second follower is fitted.
12. The digital camera according to claim 7, wherein said moving
mechanism further comprises a support plate to which the image
pick-up device is secured, said support plate being pivoted about a
shaft secured to a body of said digital camera so that said image
pick-up device is movable between said first position and said
second position, wherein said interlocking mechanism comprises: a
link bar pivoted about a shaft secured to said camera body, one end
of said link bar having a follower, the other end of said link bar
engaging with said support plate; and a cam groove formed on said
movable lens barrel, said follower being fitted in said cam
groove.
13. A digital camera having a retractable photographic lens,
comprising: an image pick-up device on which an object image is
focused through said photographic lens; and a mechanism for
positioning said image pick-up device in a photographic optical
path of said photographic lens behind said photographic lens when a
power switch of said digital camera is turned ON, and for
positioning said image pick-up device out of said photographic
optical path when said power switch is turned OFF.
.Iadd.14. A camera comprising: a plurality of optical elements; and
a lens barrel movable along an optical axis between and including a
plurality of photographic positions and at least one position in
which no photograph can be taken, and wherein when said lens barrel
is in all of said plurality of photographic positions, all of said
optical elements are positioned along the optical axis, and when
said lens barrel is in said at least one position in which no
photograph can be taken, at least one optical element of said
plurality of optical elements is positioned out of the optical
axis, and at least another optical element of said plurality of
optical elements is positioned along the optical axis, such that at
least a portion of said at least one optical element and at least a
portion of said at least another optical element are positioned
along a common plane which is generally perpendicular to the
optical axis..Iaddend.
.Iadd.15. The camera according to claim 14, wherein said at least
one optical element is an image pick-up device..Iaddend.
.Iadd.16. The camera according to claim 15, wherein said image
pick-up device is a charge-coupled device..Iaddend.
.Iadd.17. The camera according to claim 14, wherein said plurality
of optical elements includes at least one lens and an image pick-up
device..Iaddend.
.Iadd.18. The camera according to claim 17, wherein said image
pick-up device is a charge-coupled device..Iaddend.
.Iadd.19. The camera according to claim 14, wherein said plurality
of optical elements includes an image pick-up device and a
plurality of lenses..Iaddend.
.Iadd.20. The camera according to claim 19, wherein said image
pick-up device is a charge-coupled device..Iaddend.
.Iadd.21. The camera according to claim 14, further comprising a
finder configured to move in association with movement of said
barrel within said plurality of photographic
positions..Iaddend.
.Iadd.22. The camera according to claim 14, wherein said plurality
of photographic positions comprises a zoom range..Iaddend.
.Iadd.23. A camera comprising: a plurality of imaging elements; and
a lens barrel movable along an optical axis between and including a
plurality of photographic positions and at least one position in
which no photograph can be taken, and wherein when said lens barrel
is in all of said plurality of photographic positions, all of said
imaging elements are positioned along the optical axis, and when
said lens barrel is in said at least one position in which no
photograph can be taken, at least one imaging element of said
plurality of imaging elements is positioned out of the optical
axis, and at least another imaging element of said plurality of
imaging elements is positioned along the optical axis, such that at
least a portion of said at least one imaging element and at least a
portion of said at least another imaging element are positioned
along a common plane which is generally perpendicular to the
optical axis..Iaddend.
.Iadd.24. The camera according to claim 23, wherein said at least
one imaging element is an image pick-up device..Iaddend.
.Iadd.25. The camera according to claim 24, wherein said image
pick-up device is a charge-coupled device..Iaddend.
.Iadd.26. The camera according to claim 23, wherein said plurality
of imaging elements includes at least one lens and an image pick-up
device..Iaddend.
.Iadd.27. The camera according to claim 26, wherein said image
pick-up device is a charge-coupled device..Iaddend.
.Iadd.28. The camera according to claim 23, wherein said plurality
of imaging elements includes an image pick-up device and a
plurality of lenses..Iaddend.
.Iadd.29. The camera according to claim 28, wherein said image
pick-up device is a charge-coupled device..Iaddend.
.Iadd.30. The camera according to claim 23, further comprising a
finder configured to move in association with movement of said
barrel within said plurality of photographic
positions..Iaddend.
.Iadd.31. The camera according to claim 23, wherein said plurality
of photographic positions comprises a zoom range..Iaddend.
Description
.Iadd.More than one reissue application has been filed for the
reissue of U.S. Pat. No. 6,366,323. The reissue applications are
application Ser. Nos. 10/815,193 and 10/815,194 (the present
application), both filed on Apr. 1, 2004 and both of which are
reissues of U.S. Pat. No. 6,366,323..Iaddend.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a digital camera provided with an
image pick-up device such as a CCD for converting an image of an
object into electric signals.
2. Description of the Related Art
A digital camera (digital imaging camera) generally includes an
image pick-up device such as a CCD (charge-coupled device) for
converting an object image formed thereon through the photographic
lens of the camera into electric signals which are then converted
into digital signals. The digital signals are generally stored in a
recording medium such as a flash memory or a memory card in a
predetermined format.
In a conventional digital camera, it is difficult to reduce the
thickness of the camera body because a bulky image pick-up device
is positioned in the camera body behind the photographic lens. Even
if the camera is designed to have a retractable photographic lens
for the purpose of reducing the thickness of the camera body when
the camera is not in use, it is still difficult to reduce the
thickness because a sufficient space in which the photographic lens
is to retract cannot be secured in front of the bulky image pick-up
device within a thin camera body.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a digital
camera having structure which makes it possible to design the
camera body to be thin in the direction of the optical axis of the
photographic lens of the camera.
To achieve the object mentioned above, according to an aspect of
the present invention, there is provided a digital camera which
includes: a photographic lens movable along an optical axis thereof
between a retracted position and a photographing position in front
of the retracted position; an image pick-up device on which an
object image is formed through the photographic lens, the image
pick-up device being guided to be movable between a first position
where the image pick-up device is positioned in a photographic
optical path of the photographic lens behind the photographic lens
and a second position where the image pick-up device is positioned
out of the photographic optical path; and a mechanism for moving
the image pick-up device between the first position and the second
position, wherein the moving mechanism moves the image pick-up
device to the first position when the photographic lens is moved
from the retracted position to the photographing position, and
wherein the moving mechanism moves the image pick-up device to the
second position when the photographic lens is moved from the
photographing position to the retracted position.
Preferably, the image pick-up device is guided in a direction
perpendicular to the optical axis.
Preferably, the moving mechanism moves the image pick-up device
from the first position to the second position before the
photographic lens reaches the retracted position.
According to another aspect of the present invention, there is
provided a digital camera having a retractable photographic lens.
The digital camera includes: an image pick-up device on which an
object image is focused through the photographic lens; and a
mechanism for positioning the image pick-up device in a
photographic optical path of the photographic lens behind the
photographic lens when a power switch of the digital camera is
turned ON, and for positioning the image pick-up device out of the
photographic optical path when the power switch is turned OFF.
The present disclosure relates to subject matter contained in
Japanese Patent Application No. 09-155144 (filed on Jun. 12, 1997)
which is expressly incorporated herein by reference in its
entirety.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be described below in detail with
reference to the accompanying drawings in which:
FIGS. 1A, 1B and 1C are schematic sectional views of a photographic
optical system and an image pick-up unit in different positions,
showing a fundamental structure of a digital camera to which the
present invention is applied;
FIG. 2 is a perspective view of fundamental cements of a first
embodiment of the digital camera to which the present invention is
applied;
FIG. 3 is a plan view of a cam grove formed on a cam ring shown in
FIG. 2;
FIG. 4 is a perspective view of fundamental elements of a second
embodiment of the digital camera to which the present invention is
applied; and
FIG. 5 is a plan view of a cam slot formed on a cam plate shown in
FIG. 4.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1A, 1B and 1C show a fundamental structure of a digital
camera to which the present invention is applied. The camera is
provided with a zoom lens 11 consisting of two lens groups, i.e., a
front lens group L1 and a rear lens group L2. The front and rear
lens groups L1 and L2 are moved along an optical axis O of the zoom
lens 11 while varying the distance therebetween to effect zooming
and focusing.
The camera is provided with an image pick-up unit (image pick-up
device) 21. The image pick-up unit 21 is provided with a base plate
25 to which a CCD 24 is fixed. A set of filters 23 including a
low-pass filter and an infrared filter are secured to the CCD 24
between the rear lens group L2 and the CCD 24. The base plate 25 is
guided in a direction perpendicular to the optical axis O to be
selectively movable between a first position where the CCD 24 is
positioned behind the rear lens group L2 (see FIG. 1A or 1B) and a
second position where the CCD 24 is positioned out of the
photographic optical path of the zoom lens 11 (see FIG. 1C). The
base plate 25 is moved between the first and second positions by a
drive mechanism (not shown in any of FIGS. 1A, 1B and 1C). In each
of FIGS. 1A, 1B and 1C reference numeral 13 designates an inner
surface of a wall (e.g., a back wall) of a camera body of the
camera.
FIG. 1A shows the zoom lens 11 and the image pick-up unit 21 in a
photo-ready condition with the power switch of the camera turned
ON. FIG. 1B shows the zoom lens 11 and the image pick-up unit 21 in
a non-photographable condition with the zoom lens 11 retracted and
with the image pick-up unit 21 still positioned behind the rear
lens group L2. FIG 1C shows the zoom lens 11 and the image pick-up
unit 21 in a non-photographable condition with the zoom lens 11
retracted and with the image pick-up unit 21 positioned out of the
photographic optical path of the zoom lens 11. In the photo-relay
condition shown in FIG. 1A, the front and rear lens groups L1 and
L2 are each advanced forwardly with the rear lens group L2 being
sufficiently apart from the image pick-up unit 21, and the front
and rear lens groups L1 and L2 are adjusted by a focusing device
(not shown) to form a sharp object image on the light receiving
surface of the CCD 24. The camera is provided therein with an image
processing circuit (not shown). The electric image signals output
from the CCD 24 are transmitted to the image processing circuit via
a cable (not shown) to be converted by the image processing circuit
into digital data in a predetermined format. The digital data is
stored in a recording medium such as a flash memory or a memory
card, or is output from the camera.
When the power switch is turned off, the front and rear lens groups
L1 and L2 are retracted to respective rearmost positions (retracted
positions) and at the same time the image pick-up device 21 is
moved out of the photographic optical path of the zoom lens 11, as
shown in FIG. 1C. In the case where the zoom lens 11 is retracted
with the image pick-up device 21 still positioned behind the rear
lens group L2 in the photographic optical path of the zoom lens 11.
The rear lens group L2 cannot be moved back beyond the position of
the front end of the image pick-up device 21, namely, the rear lens
group L2 cannot retreat to a position where it contacts the filter
set 23. FIG. 1B shows a state where the front and rear lens groups
L1 and L2 are retracted with the image pick-up device 21 remained
to be positioned behind the rear lens group L2. In the state shown
in FIG. 1B, "A" designates a distance between the front end of the
front lens group L1 and the back surface of the base plate 25. In
FIG. 1B "C" designates the thickness of the image pick-up unit 21.
The thickness C is approximately 7 to 8 mm.
In the digital camera to which the present invention is applied,
the image pick-up unit 21, which includes the CCD 24, is moved out
of the photographic optical path of the zoom lens 11 in the
direction perpendicular to the optical axis O when the zoom lens 11
is retracted, which makes it possible to further retract the zoom
lens 11 in the camera body. Therefore, it is possible to retract
the zoom lens 11 to a position where the rear end of the rear lens
group L2 almost contacts the inner surface 13 of the camera body.
That is, if the image pick-up unit 21 is moved off the photographic
optical path, the zoom lens 11 can further retreat by a length
corresponding to thickness C of the image pick-up unit 21. It is
therefore possible to thin the camera body by thickness C (see FIG.
1C). It is otherwise possible to length a lens barrel for
supporting the zoom lens 11 by thickness C, which makes it possible
to provide the camera body with a zoom lens having a longer focal
length or a higher zoom ratio.
The image pick-up unit 21 may be moved into and out of the
photographic optical path by any drive mechanism.
The zoom lens 11 and the image pick-up unit 21 may be moved by a
common motive power source or by different motive power
sources.
FIG. 2 shows fundamental element of a first embodiment of the
digital camera to which the present invention is applied. The first
embodiment is characterized in that the image pick-up unit 21 is
inserted into and taken out of the photographic optical path by the
linear movement of a movable lens barrel 31. The image pick-up unit
21 is in the photographic optical path behind the zoom lens 11 as
shown by solid lines in FIG. 2 when the lens barrel 31 is
positioned in an advanced position (photographing position). The
image pick-up unit 21 is moved out of the photographic optical path
behind the zoom lens 11 as shown by two-dot chain lines in FIG. 2
when the lens barrel 31 retreats into the camera body.
The image pick-up unit 21 is secured to a support plate 41 having a
leg portion 42. The leg portion 42 is pivoted about a shaft 43
which extends in parallel to the optical axis O. The shaft 43 is
fixed to the camera body (not shown in FIG. 2).
A tension spring 46 extends between the support plate 41 and a pin
45 which is fixed to the camera body. The spring 46 urges the plate
41 in one direction around the shaft 43 (clockwise direction as
viewed in FIG. 2). The urged plate 41 is stopped by a locating pin
47 fixed to the camera body to position the image pick-up unit 21
to the photographing position. When the image pick-up unit 21 is in
this position, an object image is formed on the light receiving
surface of the image pick-up unit 21 through the zoom lens 11. The
image pick-up unit 21 is moved out of the photographic optical path
including the optical axis O when the support plate 41 is rotated
about the shaft 43 counterclockwise as viewed in FIG. 2 against the
spring force of the spring 46.
A link bar 51 is positioned nearby the lens barrel 31. A central
portion of the link bar 51 is pivoted about a shaft 52 extending
perpendicularly to the optical axis O. The shaft 52 is secured to
the camera body. The link bar 51 is provided at the front end
thereof with a follower pin 53. The lens barrel 31 is provided with
a cam groove 33 in which the follower pin 53 is fitted. The other
end 48 of the link bar 51 is bent to have an engaging portion 54
which is engaged with an upper edge of the leg portion 42 of the
support plate 41. When the link bar 51 rotates clockwise as viewed
in FIG. 2, the support plate 41 is rotated counterclockwise about
the shaft 43 by the rotational movement of the link bar 51 to be
positioned in a retracted position (shown by two-dot chain line in
FIG. 2) against the spring force of the spring 46.
FIG. 3 shows the contour of the cam groove 33. The cam groove 33
includes a zooming section between T and W which extends in
parallel with the optical axis O. The lens barrel 31 is moved
linearly, without rotating about the optical axis O. When the lens
barrel 31 is moved linearly to effect zooming, the follower pin 53
is fitted in the cam groove 33 within the zooming section between T
and W. This maintains the link bar 51 in the position (shown by
solid lines in FIG. 2) when the bar 51 does not turn the support
plate 41 from its photographing position to retracted position. The
cam groove 33 also includes a retracting section between W and S
which extends inclined to the optical axis O and the zooming
section between T and W. When the lens barrel 31 is retracted upon
the power switch being turned OFF, the cam pin 53 moves from the
zooming section between T and W to the end 33a of the retracting
section between W and S, which turns the link bar 51 to the
retracted position shown by two-dot chain lines in FIG. 2.
FIG. 4 shows fundamental elements of a second embodiment of the
digital camera to which the present invention is applied. The
digital camera is provided with a motor-driven zoom lens, the basic
structure of which is disclosed in, e.g., Japanese Laid-Open Patent
Publication 62-285632. The camera is provided with a zoom lens
barrel block 101, a finder and strobe block 112, a distance
measuring device, and a zoom motor 116. The distance measuring
device includes a set of light emitter and receiver 113. Those
components 101, 112, 113 and 116 are supported by or mounted on the
camera body.
The barrel block 101 is provided with a cam ring 102, a front
barrel 103 and a rear barrel 104. Each of the barrels 103 and 104
is fitted in the cam ring 102 and is moved forwardly and rearwardly
by the rotation of the cam ring 102. The barrels 103 and 104
support front and rear lens groups L1 and L2 (not shown in FIG. 4)
thereinside, respectively. Each barrel can be moved between a
retracted position and a photographing position. Each barrel is
moved within a zooming range including the photographing position
as the cam ring 102 rotates.
The finder and strobe block 112 is provided with a zoom finder 118
and a strobe 119. In accordance with the variation in the focal
length of the zoom lens 11, the finder 118 changes its
magnification and field of view while the strobe 119 changes its
angle of illumination.
The cam ring 102 is provided on an outer periphery thereof with a
sector gear 105 which extends along the circumference of the cam
ring 102. The sector gear 105 meshes with a drive pinion 107 which
is fixed to the drive shaft of the zoom motor 116. The sector gear
105 also meshes with a driven pinion 120 which is fixed to the
front end of a shaft 121 which extends in parallel to the optical
axis O. The shaft 121 is provided at the rear end thereof with a
first gear 122a. This first gear 122a meshes with a second gear
122b which meshes with a rack 123a formed on a cam plate 123. The
first and second gears 122a and 122b constitute a reduction gear
train 122 for transmitting rotation of the cam ring 102 to the rack
123a while lowering the output speed. Accordingly, the rotation of
the cam ring 102 is transmitted to the cam plate 123 through the
sector gear 105, the driven pinion 120, the shaft 121, the
reduction gear train 122 and the rack 123a. The rotational position
(angular position) of the ring 102 is detected through a code plate
130 secured to the outer periphery of the ring 102 and conductive
brushes 131 slidably contracting the code plate 130.
The cam plate 123 is guided horizontally in a direction
perpendicular to the optical axis O of the zoom lens. The cam plate
123 is provided along a rear end thereof with a downwardly
extending bent portion 123b. The aforementioned rack 123a, which
meshes with the second gear 122b, is formed on the bottom end of
the bent portion 123b therealong. The cam plate 123 is provided
with a first cam slot 125 for varying the magnification of the
finder 118 and a second cam slot 127 for varying the angle of
illumination of the strobe 119.
The finder optical system of the finder 118 consists of three lens
groups, i.e., a fixed object lens group L3, a fixed eyepiece lens
group L4 and a movable lens group L5 positioned between the object
lens group L3 and the eyepiece lens group L4. The magnification of
the finder 118 varies by moving the movable lens group L5 along the
optical axis of the finder 118. The movable lens group L5 is
provided with a follower pin 118a which is fitted in the first cam
slot 125. The movable lens group L5 is moved to vary the
magnification of the finder 118 such that the field of view of the
finder 118 is coincident with the size of a picture which is varied
due to the variation of the focal length of the zoom lens in the
barrel block 101.
As the focal length of the zoom lens becomes longer, the strobe 119
narrows the angle of illumination. For a close shot, the strobe 119
widens the angle of illumination, reducing the illuminance level of
an object which is to be photographed. For this, the strobe 119 is
provided with a fixed Fresnel lens L6 and a reflector 129 which
holds a xenon lamp (not shown). The reflector 129 is provided with
a follower pin 119a which is fitted in the second cam slot 127 so
as to be driven to move along its optical axis by the movement of
the cam plate 123.
The turning of the cam ring 102 causes the cam plate 123 to move
right and left. When the zoom lens 11 is retracted, i.e., when the
front and rear barrels 103 and 104 are retracted, the cam plate 123
is positioned in its position closest to the barrel block 101. When
the zoom lens 11 is positioned within the photographing range, that
is, within the zooming range, the cam plate 123 is away from the
barrel block 101. This second embodiment is characterized in that
the image pick-up unit 21 is moved between the photographing
position and the retracted position by the movement of the cam
plate 123.
The contour of each of the first and second cam slots 125 and 127
is determined in association with the rotational position (angular
position) of the cam ring 102. Namely, the contour of each cam slot
is determined such that points T, W and S of each cam slot
correspond to a telephoto-extremity angular position A, a
wide-angle-extremity angular position B and a retracted angular
position C of the cam ring 102, respectively. The section of each
cam slot between the points T and W is determined to correspond to
the angle of rotation of the cam ring 102 between the angular
positions A and B. Likewise, the section of each cam slot between
the points W and S is determined to correspond to the angle of
rotation of the cam ring 102 between the angular positions B and C.
The sections between the points T and W of the first and second cam
slots 125 and 127 are each inclined relative to the direction of
movement of the cam plate 123 so as to vary the magnification of
the finder 118 and the angle of illumination of the strobe 119,
respectively, in accordance with the variation of the focal length
of the zoom lens 11. The retracting sections between the points W
and S of the first and second cam slots 125 and 127 are each
parallel with the direction of movement of the cam plate 123, so
that neither the magnification of the finder 118 nor the angle of
illumination of the strobe 119 varies as long as the follower pins
118a and 119a move within the sections between W and S of the cam
slots 125 and 127, respectively. Rotation of the cam ring 102
between its angular positions B and C, which respectively
correspond to the points W and S, causes the image pick-up unit 21
to move between the photographing position (shown by solid lines in
FIG. 4) and the retracted position (shown by two-dot chain lines in
FIG. 4).
The image pick-up unit 21 is secured to a support plate 61 which
lies in a plane perpendicular to the optical axis O of the zoom
lens 11. The support plate 61 is provided with an L-shaped leg
portion 62. An end of the leg portion 62 is bent rearwards and
further bent upwards to form a crank portion 62a having an L-shape
cross section. The crank portion 62a is pivoted about a shaft 63
which extends in parallel with the optical axis O. The shaft 63 is
fixed to the camera body (not shown).
A tension spring 66 extends between the support plate 61 and a pin
65 which is fixed to the camera body. The support plate 61 is urged
in one direction by the spring 66 and stopped by a locating pin 67
fixed to the camera body to position the image pick-up unit 21 in
the photographing position. When the image pick-up unit 21 is in
the photographing position, an object image is formed on the light
receiving surface of the image pick-unit 21 through the zoom lens
11. The support plate 61 can be rotated about the shaft 63 against
the spring force of the spring 66 to move the image pick-up unit 21
out of the photographic optical path including the optical axis
O.
The bent portion 123b of the cam plate 123, which is provided with
the rack 123a, is provided at one end thereof closer to the image
pick-up unit 21 with a pusher 123c, which is formed as an extension
of the bent portion 123b. Rotation of the zoom motor 116 in the
direction to retract the zoom lens 11 causes the cam plate 123 to
move toward the retracted position (to the left as viewed in FIG.
4), which causes the tip of the pusher 123c contact and pushes the
upper end 64 of the crank portion 62a of the support plate 61. This
turns the support plate 61 towards its retracted position against
the spring force of the spring 66. Before the cam plate 123 reaches
its retracted position, the image pick-up unit 21 is moved off the
photographing optical path as shown by two-dot chain lines in FIG.
4. The cam plate 123 is provided with a slit 123d in which part of
the image pick-up unit 21 can move so as not to interfere with the
cam plate 123 when it moves to its retracted position.
Rotation of the zoom motor 116 in the retracting direction causes
the rear barrel 104 and the rear lens group L2 to retreat towards
their retracted positions previously occupied by the image pick-up
unit 21 (refer to FIG. 1C).
Rotation of the zoom motor 116 in the advancing direction causes
the rear barrel 104 and the rear lens group L2 to move forwardly,
which causes the cam plate 123 to move towards the telephoto
extremity position thereof, i.e., in a direction apart from the
barrel block 101. The movement of the cam plate 123 in this
direction moves the pusher 123c away from the upper end 64 of the
crank portion 62a of the support plate 61. This causes the support
plate 61 to turn towards its photographing position through the
spring force of the spring 66. Further movement of the cam plate
123 causes the image pick-up unit 21 to move into the photographic
optical path, where the rear barrel 104 and the rear lens group L2
are already absent. When the cam plate 123 reaches its wide-angle
extremity position, the pusher 123c leaves the upper end 64 of the
crank portion 62a. Consequently, the spring 66 brings the support
plate 61 into contact with the locating pin 67. While the zoom lens
11 is driven to effect zooming and focusing, the cam plate 123
moves within a range where its pusher 123c is apart from the upper
end 64 of the crank portion 62a, so that the image pick-up unit 21
remains in the photographing position, where the spring 66 holds
the support plate 61 to contact the locating pin 67.
After the power switch (not shown) of the camera shown in FIG. 4 is
turned off, the zoom motor 116 rotates in the retracting direction
to retract the lens barrels 103 and 104. At the same time, the cam
plate 123 slides in the retracting direction. This first turns the
support plate 61 toward its retracted position to move the image
pick-up unit 21 out of the photographing optical path. After the
image pick-up unit 21 moves off the photographing optical path, the
rear barrel 104 moves into the position previously occupied by the
image pick-up unit 21. Consequently, the rear end of the rear
barrel 104 or the rear lens group L2 moves rearwardly to a position
close to the inner surface 13 of the camera body (see FIG.
1(C)).
As can be understood from the foregoing, according to the digital
camera to which the present invention is applied, when the
photographic lens retreats in the camera body, the image pick-up
unit 21, which is positioned behind the photographic lens, is moved
out of the photographic optical path to secure the space behind the
lens in which the rear end of the photographic lens can further
retreat. It is therefore possible to reduce the thickness of the
camera body, or lengthen the movable lens barrel in order to
increase the zoom ratio.
In each of the first and second embodiments, although the image
pick-up unit 21 is secured to the support plate (41 or 61) which is
pivoted about the shaft (43 or 63) extending parallel to the
optical axis O so as to move the image pick-up unit 21 into and out
of the photographic optical path, the image pick-up unit 21 can be
guided in a direction perpendicular to the optical axis so as to be
driven to linearly move into and out of the photographic optical
path.
In each of the first and second embodiments, the zoom lens 11 and
the image pick-up unit 21 can be driven by different motive power
sources.
Obvious changes may be made in the specific embodiments of the
present invention described herein, such modifications being within
the spirit and scope of the invention claimed. It is indicated that
all matter contained herein is illustrative and does not limit the
scope of the present invention.
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